Can anyone give advice on getting into good colleges?

Here is a question from my nephew: I am 15 years old, currently in my first year of high school and seriously thinking about how to get into a good college. I get only straight A, play varsity level soccer, and juggle different extra curricular activities, like speech and debate. My mom was south korean and my dad is like English. I live in a small town in Colorado and go to a pretty small high school. I am trying really hard to make the right decisions for my future so I could use some advice on what classes to take. I want to go to a great college, like Harvard. Can anyone give some comment on this topic? Which college do you think is best in the United States? What makes you think so?

As far as colleges go, I went to the local Jr. college and live in a town with a University and am now going there.
But for advice I can share what I know:
1)Never hesitate to take a scholarship because of your racial background.
2)If there is something that you know you want to do then find a way to volunteer at it. If you want to be a doctor then volunteer at the hospital ect.
3)Do not burn yourself out on school, but if you can take advanced classes, or summer classes, do it. In my area you can take college classes in your Jr. and senior year of high school. If that is an option then try and do it. As a warning, you will have to work hard in those classes.
4) it is good that you do sports, speech, and debate. Have you thought about a foreign language? In some states you have to have it to graduate High School but a working knowledge of another language can help for college also.
5) Have fun in High School (that does not mean stupid fun, but real fun), make new friends, try new things, but don't forget to study, it is the most important skill you can have in college, being able to study effectivly
6) There is nothing wrong with Ivy League schools, but in most cases you can get the same education for a better price going to a state university.
I hope this helps. The most important thing is to have a dream and never let it go, work for it because you CAN do what you are willing to work for.